Bittersweet nightshade is close relative of the tomato

As I sat on my porch last weekend, enjoying a day without any rain, I noticed a new development over by the stairs. A new plant had made an appearance up to the level of the deck boards. But I should probably rephrase that. This is simply a new addition to the deck, for I have known this particular species for a very long time. The plant I am speaking of is the bittersweet nightshade (Solanum dulcamara).

Although I have known this plant for decades, I only recently learned its proper name. My mother introduced it to me as deadly nightshade when I was a kid and so that’s what I’ve always called it. But that’s the problem with common names isn’t it? She could have called it anything and I would have believed her.

In fact, this species does have an impressive list of common names including: woody, climbing, bitter, and trailing nightshade, as well as bittersweet, blue bindweed, scarlet berry, fellenwort, poisonberry, felonwood, violet bloom, snakeberry and poisonflower.

Perhaps more interesting, however, are the common names that are missing from this list. I would have expected at least one of them to be something like “wild tomato,” or “devil’s tomato,” or something like that. The reason you ask? That’s simple. Bittersweet nightshade is actually very closely related to the cultivated tomato (Solanum lycopersicum).

Remarkable resemblance

The resemblance between nightshade and tomato is actually quite stunning when you get a chance to really look at things up close. Both plants grow in the form of a tough, climbing vine that is almost woody in its growth form.

Both produce flowers with five sharply pointed petals, but they differ in the color of the flower. Bittersweet nightshade produces flowers that are a deep violet, whereas the cultivated tomato has yellow flowers.

The fruits of the two plants are almost identical. Everyone knows what a cherry tomato looks like, so everyone should notice the similarity between a cherry tomato and a bittersweet nightshade berry. Like tomatoes, the nightshade berries start off as a light green color and then as the fruit ripen they progress from green, to light yellow, to a pale orange, and finally a deep red. Sound familiar to anyone?

It is thought that the cultivated tomato got its start in South America. Peru has the largest variety of wild tomatoes and it is speculated that the plants traveled via trade routes to Mexico, which seems to be where the domestication of the tomato first began. As soon as the Spanish arrived, the tomato was introduced to the rest of the world.

The most remarkable thing about this story is the fact that so many members of the nightshade family are toxic. There must have been a lot of trial and error on the part of early humans to determine which plants were good to eat and which weren’t. I don’t envy the official taste testers of the “good old days.”

Where to find them

If you want to find a bittersweet nightshade of your own, you need only keep your eyes open. The plants grow almost anywhere, but you can’t really predict where you will find them. Since they are vines, they tend to be found in out-of-the-way corners where they can grow without being cut.

The place I am always surprised to see them is growing up the fence in the parking lot at school. Just keep your eyes peeled and you’ll be sure to see one sooner or later.

Bill Danielson is a professional nature photographer and author living in Altamont. Contact him at www.speakingofnature.com.